Coincidence senser



June 18, 1957 1 MACKTA corNcInENcE sENsER Filed Dec. 29, 1954 .n.mHu

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COINCIDENCE SENSER Filed Dec. 29. 1954 2 Shets-Sheet 2 F'IE'.E

ATTORNEY L'] H Ll.

'a E Y 5 u b s Yu U l2 k k 2 o 5 3. o Q( 2 E' i B INVENTOR. ""w l Leo MAcKTA w- N United Seres. Faremo" CGINCIDENCE SENSER Leo Mackta, Brooklyn, N. Y.

Application December 29, 1954, Serial No.'478,447

4 Claims. (Cl. 315-8.5)

This invention relates to computers, and more particularly to a register comparator for digital computers.

A main object of the invention is to provide a novel and improved device for comparing a plurality of pairs of voltages, currents, or pulses, to provide a signal or response when all the pairs are matched, said device being simple in construction, being reliable in operation, and involving only a few parts.

A further object of the invention is to provide an improved cathode ray tube which may be employed as a coincidence senser to determine coincidence in the conditions of a plurality of pairs of storage elements in a digital computer or similar counting device, said cathode ray tube being relatively inexpensive to fabricate, and providing an accurate indication when the conditions in said respective pairs of storage elements are matched.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a diagrammatic view showing one form of coincidence senser for a plurality of pairs of register dip-flops in accordance with the present invention, wherein the coincidence sensing tube employs electrostatic delection.

Figure 2 is a transverse vertical cross-sectional view taken substantially on the line 2-2 of Figure l and showing the relation of certain of the elements of the coincidence sensing tube around the longitudinal axis thereof.

Figure 3 is a transverse vertical cross-sectional view taken substantially on the line 3-3 of Figure l.

Figure 4 is a diagrammatic view generally similar to Figure 1 but showing a modied form of coincidence sensing tube according to the present invention, employing magnetic deflection.

Figure 5 is a transverse vertical cross-sectional view taken substantially on line 5-5 of Figure 4.

In digital computers now known in the art, there are registers consisting of vacuum tubes or saturable magnetic cores which hold information. In the case of vacuum tubes, each tube is either conducting or nonconducting, with the result that the plate potential thereof is either a denite high value or a definite low value. For example, in Figure l, a computer is shown which may comprise respective ip-ops 11, 12, 13 and 14, and respective flip-tlops 11', 12', 13' and 14', each having a storage tube having a plate 15.

Designated generally at 22 is a cathode ray tube having the heater filament 23, the cathode 24, the control grid 25, the focus ring 26, and the accelerating anode ring 27, arranged at one end of the tube on the longitudinal axis thereof. At the opposite end of the cathode ray tube is the at centrally apertured main collecting anode 28 arranged concentrically with said longitudinal axis, and suitably mounted in the central aperture of anode 28 and insulated therefrom is another collecting anode 29, located on said longitudinal axis.

Anode 2S is connected by a wire 30 to the positive terminal of a conventional voltage source, such as the serially connected batteries 31 and 32, the accelerating anode ring 2.7 being connected by a wire 33 to the positive terminal of battery 31 in the usual manner. Connected in series with batteries 31 and 32 are a bias battery 34 and the winding of a focus potentiometer 35. The focus electrode 26 is connected to the sliding tap 36 of potentiometer 35 by a wire 37. Cathode 24 is connected to the negative terminal of bias battery 34 by a wire 38.

Arranged spirally along the tube 22 and supported therein in any suitable manner are respective electrostatic dellecting plates 39, 40, 41 and 42, and arranged diametrically opposite these plates are the respective cooperating electrostatic dellecting plates 39', 40', 41 and 42'-. The respective plates 39 to 42 have terminals 43 to 46 which are connected respectively to the anodes 15 of the storage tubes of flip-flops 11 to 14. Similarly, the deecting plates 39' to 42' have terminals 43' to 46 which are connected respectively to the anodes 15 of the storage tubes of flip-Hops 11 to 14'.

The center collecting anode 29 is connected by a wire 47 to a suitable detector means, for example, to the grid of a detector tube 48. A load resistor 49 is connected between wire 47 and wire 30 to provide a suitable return path for electrons collected by anode 29.

It will be apparent that when the electron beam 50 of tube 22 is undeviated by the deecting plates 39, 39', 40, 46', 41, 41', and 42, 42', the beam 50 will impinge on anode 29, providing a signal on the grid of detector tube 48. When any deviation occurs, due to a deection produced by any of the electrostatic plates, the electron beam 50 will strike the main collecting anode 28, and there will be no. signal in tube 48.

It will be further apparent that if a matched set of signal conditions in the ip-ops 11 to 14 and 11 to 14' is present, therewill be no deviation of the electron beam 50. Thus, for example, if the storage tubes of both ipops 11 and 11' are conducting, equal relativelylow voltages will be present on their anodes, and equal voltages will appear on the deliection plates 39, 39', causing no deflection of the electron beam 50. Any unbalance in the symmetry of the conditions of conduction or nonconduction of the respective tube systems 11 to 14 and 11' to 14' will be sufficient to cause deviation of the electron beam 50.

The electron beam 50 may be either modulated or unmodulated, for example, may be either steady or pulsed, the modulations of the beam being controlled at the grid 25. When coincidence occurs, the beam, unmodulated or modulated, will cause a corresponding signal to be placed on the grid of the detector tube 48.

Obviously, the number of pairs of dellection plates will be in accordance with the number of pairs of llip-ops in the registers being compared. As many as fty pairs of voltages (involving fty pairs of flip-flops) may be compared by providing the corresponding number of spirally arranged sets of deflection plates in the cathode ray tube. The deection plates must, of course, be staggered in position, so that a deflection produced by a plate will not be compensated for by a deflection produced by a plate associated with a diierent pair of tubes of the system.

In the form of the invention illustrated in Figures 5 and 6, respective saturable magnetic cores 51 to 54 are arranged spirally around the cathode ray tube, shown at 22', and are supported in any suitable manner. Diametrically opposite these cores are the cooperating magnetic cores 51', 52', 53 and 54. The saturable magnetic cores 51 to 54 comprise one register and the saturable magnetic cores 51 to 54' comprise the other register of the computer. Each core is provided with a suitable magnetizing Winding connected in a conventional manner in a respective register circuit. As in the previously described embodiment of the invention, any unbalance in the symmetry of the conditions of the magnetic cores 51 to 54 withV respect to cores 51 to 54' will cause a deviation of the electron beam 50 and there will then be no signal on the grid of detector tube 48. When coincidence of such conditions'occurs in the respective pairs of magnetic'cores, the beam 50 Will impinge on the center collecting anode 29, causing av signal to appear on the grid of detector tube 48.

As shown, the cores may be mounted with their axes parallel to the'axis of the cathode ray tube 22. There is suflicient magnetic leakage from the cores to produce deflection of the electron beam 50.

The cathode ray tube in either of the embodiments of the invention described above preferably should have a relatively low .accelerating4 voltage on the accelerating anode 27 to provide increased sensitivity of the beam to deection voltages. I

While certain specific embodiments of coincidence sensing devices for computers have been disclosed in the foregoing description, it will be understood that various moditications within thespirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is: v

l. A register coincidence sensing device comprising a plurality of respective pairs of counter tubes, each being formed and arranged to store a signal therein, a cathode ray tube having a pair of concentrically arranged collecting anodes, an electron gun assembly arranged to produce an electron beam directed to normally impinge on the inner collecting anode, a plurality of pairs of diametrically opposed deflection-producing elements spaced longitudinally along the tube between said electron gun assembly and said collecting anodes, said pairs of dellectionproducing elements being located on diameters at different angles around an axis dened by the normal path of said electron beam, means connecting each pair of counter tubes in circuit with a respective pair of diametrically opposed deection-producing elements, whereby suicient deflection of the electron beam is produced by unbalance of the conditions of the tubes to deviate the beam from said inner collecting anode, and detector means connected to one of said collecting anodes.

2. In a computer including a sequence of pairs of signal storage devices, means determining coincidence of the signals in the sequencevof respective storage devices comprising a pair of concentrically arranged collecting anodes an electron gun assembly formed and arranged to provide an electron beam directed to normally irnpinge on the inner collecting anode and to impinge on the outer anode when deflected from its normal path, means applying the signals of the respective storage devices in opposition at opposite sides of the beam at diameters spaced longitudinally along said beam and inclined at dilerent angles around an axis defined by the normal path of the beam, whereby said beam is deflected from said normal path in response to lack of coincidence of the respective signals in the sequence ofpairs of storage devices, and detector means connected to one of said collecting anodes.

3. In a computer including a sequence of pairs of signal storage devices, means determining coincidence of the signals in the sequence of respective pairs of storage devices comprising a pair of concentrically arranged co1- lecting anodes, an electron gun assembly formed and arranged to provide an electron beam directed to normally impinge on the inner collecting anode and to impinge on the outer anode when deliected from its normal path, a sequence of respective pairs of opposed electrostatic plates located at opposite sides of the beam at diameters spaced longitudinally along said beam and inclined at different angles Yaround .an axis defined by the normal path of the beam, means applying the signals of the respective pairs Y of storage devices to the respective pairs of opposed electrostatic plates, whereby said beam is deccted from said normal path in response to lack of coincidence of the respective signals in the sequence of pairs of storage devices, and detector means connected to one of said collecting anodes.

4. In a computer including a sequence of pairs of signal storage electromagnets, means determining coincidence of the signals in the sequence of respective pairs of storage electromagnets comprising a pair of concentrically arranged collecting anodes, an electron gun assembly formed and arranged to provide an electron beam directed to normally impinge on the inner collecting anode and to impinge on the outer anode when deiiected from its normal path, means mounting the respective pairs of storage electromagnets in opposition at opposite sides of the beamat diameters spaced longitudinally along said beam and inclined at different angles around an axis detined by the normal path of the beam, whereby said beam is deflected from said normal path in response to lack of coincidence of the respective signals in the sequence of pairs of storage electromagnets, and detector means connected to one of said collecting anodes.

References Cited in the tile of this patent UNITED STATES PATENTS 2,011,920 Terry Aug. 20, 1935 2,159,818 Plaistowe May 23, 1939 2,191,185 Wolf Feb. 20, 1940 .2,229,698 Hollmann Jan. 28, 1941 2,335,675 Holters et al. Nov. 30, 1943 2,463,617 Hartley Mar. 8, 1949 2,677,779 Goodrich May 4, 1954 

